Engine operating time hourmeters frequently are used in outdoor power equipment to monitor engine run time to let the owner and/or manufacturer of the outdoor power equipment monitor how long the engine has run, when the equipment is due for repair/maintenance service, and whether the equipment is still under warranty. Examples of outdoor power equipment can include, but are not limited to, tractors, lawn and garden tractors, all terrain vehicles (ATVs), mowers, push mowers, marine vehicles, boats, jet skis, and the like.
Different engines can generate different signals that the hour meter can use to monitor the engine run time. Older carbureted engines can generate high voltage, positive or negative magneto pulses, which can indicate the engine is running. Newer electronic fuel injection (EFI) engines can generate a low voltage signal to indicate that the engine is running. Other types of engines can emit other types of signals to indicate that the engine is running, such as a signal related a fuel pump or other component being activated, or a signal related to a key being turned on. However, hour meters generally cannot detect more than one type of signal. Accordingly, to detect the different types of signals, manufacturers generally have employed different hour meters with special circuitry to detect each of the different types of signals.
Further discussion relating to the developments in the hour meter are found, for example, in U.S. Pat. Nos. 7,812,473, 7,154,814, 7,034,674, 6,609,357, and 6,377,168, all assigned to the Delta Systems, Inc. of Streetsboro, Ohio (hereinafter collectively “Patents”). The Patents are incorporated herein by reference in their entirety.